Depends on the kind of story. Is it going for a realistic, hypothetically plausible near-future vibe? Something like The Expanse? If so, I wouldn't use aliens unless the story was about them.

Otherwise, I like me some creatures and aliens.

Aliens do, however, force you to spend words describing them and maybe even worldbuilding out their distinctness from humanity. Which can be super fun and enrich your story, but might distract from the story, depending on what its goals are.

If the answer is "check a box" I'd suggest that's not sufficient. If the answer is "advance the timbre of 'speculative fiction' while allowing me to delve into [concept A and B that further my theme]" then heck and yes it's a good idea.

Aliens are a great canvas on which you can paint so very many things that "checking a box to make it seem more science-fiction-ey" seems like it does it a disservice. Call me crazy, but I'd say that best case scenario adding something "just to check a box" will end up a net neutral. Worst case scenario, it appears a transparent add that is actively detrimental to the story.